A spark from a nearby chimney started a massive blaze which destroyed part of a Te Puke sawmill.
About 35 firefighters from Te Puke, Papamoa, Greerton and Mount Maunganui were called to fight the blaze at Pukepine Sawmills on Jellico St about 6.40pm yesterday.
Te Puke fire chief Glenn Williams said the first fire crew arrived to find part of the plant well ablaze.
"There was a saw dust delivery hopper that caught fire and an adjacent storage building and part of a conveyor system that delivers sawdust to the hopper," he said.
Mr Williams said there was no one on site at the time of the fire.
"We believe that it was [caused by] a spark from a chimney stack that ignited sawdust on the roof of the building."
The damage was expected to keep at least that part of the plant closed down for a few days.
Mr Williams said the difficulty with fighting the fire was connecting to a water source that allowed firefighters to reach all parts of the large site.
The first appliance to arrive ran out of water before it could be connected to a source, he said.
Firefighters were on site for about two and a half hours.